The multitude of ancillary costs associated with any technology are almost impossible to calculate. I always wonder how much of the cost of an oil change for my car should be deducted from the good of hauling a sack of recyclable pop bottles to the center.
But there is one sure way it can be calculated: the free market. Stop ALL government subsidies and you quickly find the true value and worth of each and every component of every technology. And no, all electric cars make no more sense than a $13 60W light bulb. The government does NOT pick winners and loosers -- just losers.

An impressive way to demonstrate the potential of solar power and batteries. Taking off in the morning with full batteries allows heavy power consumption at take-off and then an extended period for the batteries to recharge while flying in the sunlight before nightfall. With radar, autopilot, and a dedicated flight path, the human pilot could take catnaps enroute to Europe. Once people see such feats achieved, maybe they won't push back so strongly against proven gas saving technologies like hybrid vehicles. Unfortunately cars cannot afford the area of two glider wings to recharge their batteries as a pure electric device.

For some reason, this story reminded me of an episode of Star Trek Next Generation (IIRC). In this episode, CAPT Jean Luc Picard (interesting coincidence) piloted a replica of an old spaceship, propelled by solar wind.
Now I'm confused. What is present and what was future?

In comparing the cost of solar vs. conventional, are you including the total cost? For example the value of the mountain tops blown off by coal mining and the even greater environmental damage associated with CO2 emissions. some economists dismiss these as "externalities." Can we continue to do so?

Question harder. Today I pay $0.11/kWh, but only $0.08/kWH from PV installed and operated by Solar City on my home. And if home assessors would only value a 25-year asset beyond 7 years, I could buy the array outright and have the salvage value reflected in my home valuation. And that doesn't even include the hidden costs of health care, environmental clean-up, global climate change, etc. that are clearly missing from asserting the cost of PV is more.

It is just a proof of concept - a pretty impressive one, at that. But the Voyager airplane that flew non-stop around the world a number of years ago was just a proof of concept, as was the write flyer. You've go to start someplace.
What I find astounding is that just a few years ago, doing something like this was completely unthinkable. It looked like an impossible task.
The other thing about this trip that I see is that there's nothing really revolutionary. It utilizes improvements in battery technology, light weigh structures, solar cells and motors. But there hasn't been some single breakthrough that made it possible.

I appland the effort being undertaken with the solar plane and like the battery night time flying solution. The innovation is critical to get others thinking outside of the box. I still question the cost to produce solar power vs the traditional power generation cost. If and when solar can be competitive with water/coal/etc power generation costs then we will see a revolution. Until then, it is a neat concept but only a proof of concept and not a real world solution. Again, I love the idea but question the cost.